view fs/cifs/TODO @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
line source
1 Version 1.39 November 30, 2005
3 A Partial List of Missing Features
4 ==================================
6 Contributions are welcome. There are plenty of opportunities
7 for visible, important contributions to this module. Here
8 is a partial list of the known problems and missing features:
10 a) Support for SecurityDescriptors(Windows/CIFS ACLs) for chmod/chgrp/chown
11 so that these operations can be supported to Windows servers
13 b) Mapping POSIX ACLs (and eventually NFSv4 ACLs) to CIFS
14 SecurityDescriptors
16 c) Better pam/winbind integration (e.g. to handle uid mapping
17 better)
19 d) Kerberos/SPNEGO session setup support - (started)
21 e) NTLMv2 authentication (mostly implemented)
23 f) MD5-HMAC signing SMB PDUs when SPNEGO style SessionSetup
24 used (Kerberos or NTLMSSP). Signing alreadyimplemented for NTLM
25 and raw NTLMSSP already. This is important when enabling
26 extended security and mounting to Windows 2003 Servers
28 f) Directory entry caching relies on a 1 second timer, rather than
29 using FindNotify or equivalent. - (started)
31 g) A few byte range testcases fail due to POSIX vs. Windows/CIFS
32 style byte range lock differences. Save byte range locks so
33 reconnect can replay them.
35 h) Support unlock all (unlock 0,MAX_OFFSET)
36 by unlocking all known byte range locks that we locked on the file.
38 i) quota support (needs minor kernel change since quota calls
39 to make it to network filesystems or deviceless filesystems)
41 j) investigate sync behavior (including syncpage) and check
42 for proper behavior of intr/nointr
44 k) hook lower into the sockets api (as NFS/SunRPC does) to avoid the
45 extra copy in/out of the socket buffers in some cases.
47 l) finish support for IPv6. This is mostly complete but
48 needs a simple conversion of ipv6 to sin6_addr from the
49 address in string representation.
51 m) Better optimize open (and pathbased setfilesize) to reduce the
52 oplock breaks coming from windows srv. Piggyback identical file
53 opens on top of each other by incrementing reference count rather
54 than resending (helps reduce server resource utilization and avoid
55 spurious oplock breaks).
57 o) Improve performance of readpages by sending more than one read
58 at a time when 8 pages or more are requested. In conjuntion
59 add support for async_cifs_readpages.
61 p) Add support for storing symlink info to Windows servers
62 in the Extended Attribute format their SFU clients would recognize.
64 q) Finish fcntl D_NOTIFY support so kde and gnome file list windows
65 will autorefresh (partially complete by Asser). Needs minor kernel
66 vfs change to support removing D_NOTIFY on a file.
68 r) Add GUI tool to configure /proc/fs/cifs settings and for display of
69 the CIFS statistics (started)
71 s) implement support for security and trusted categories of xattrs
72 (requires minor protocol extension) to enable better support for SELINUX
74 t) Implement O_DIRECT flag on open (already supported on mount)
76 u) Create UID mapping facility so server UIDs can be mapped on a per
77 mount or a per server basis to client UIDs or nobody if no mapping
78 exists. This is helpful when Unix extensions are negotiated to
79 allow better permission checking when UIDs differ on the server
80 and client. Add new protocol request to the CIFS protocol
81 standard for asking the server for the corresponding name of a
82 particular uid.
84 v) Add support for CIFS Unix and also the newer POSIX extensions to the
85 server side for Samba 4.
87 w) Finish up the dos time conversion routines needed to return old server
88 time to the client (default time, of now or time 0 is used now for these
89 very old servers)
91 x) Add support for OS/2 (LANMAN 1.2 and LANMAN2.1 based SMB servers)
93 y) Finish testing of Windows 9x/Windows ME server support (started).
95 KNOWN BUGS (updated April 29, 2005)
96 ====================================
97 See http://bugzilla.samba.org - search on product "CifsVFS" for
98 current bug list.
100 1) existing symbolic links (Windows reparse points) are recognized but
101 can not be created remotely. They are implemented for Samba and those that
102 support the CIFS Unix extensions, although earlier versions of Samba
103 overly restrict the pathnames.
104 2) follow_link and readdir code does not follow dfs junctions
105 but recognizes them
106 3) create of new files to FAT partitions on Windows servers can
107 succeed but still return access denied (appears to be Windows
108 server not cifs client problem) and has not been reproduced recently.
109 NTFS partitions do not have this problem.
110 4) debug connectathon lock test case 10 which fails against
111 Samba (may be unmappable due to POSIX to Windows lock model
112 differences but worth investigating). Also debug Samba to
113 see why lock test case 7 takes longer to complete to Samba
114 than to Windows.
116 Misc testing to do
117 ==================
118 1) check out max path names and max path name components against various server
119 types. Try nested symlinks (8 deep). Return max path name in stat -f information
121 2) Modify file portion of ltp so it can run against a mounted network
122 share and run it against cifs vfs.
124 3) Additional performance testing and optimization using iozone and similar -
125 there are some easy changes that can be done to parallelize sequential writes,
126 and when signing is disabled to request larger read sizes (larger than
127 negotiated size) and send larger write sizes to modern servers.
129 4) More exhaustively test against less common servers. More testing
130 against Windows 9x, Windows ME servers.